Crossing the Line

You go on spring break vacation with your close ones. Your stepmom messes up the reservations and you have to share a room with your stepsister. She tells you to mind your own business but you annoy her just for the sake of it. Early in the morning she wakes up horny. She starts touching herself and plays a porn video on her phone not realising the volume is turned all the way up. She turns it off as fast as she can, checking on you and continuing to do her thing. She doesn’t realise that you’re awake listening to her moans. You decide not to say anything and see where this goes as you already got hard. She watches the video quietly and masturbates. A few minutes in, she feels your cock on her ass. Assuming you're just having a wet dream, she humps it. She’s breathing heavily and she’s all in. She slips your cock into her wet pussy and moves her hips. You thrust back and freak her out. She yells at you saying how inappropriate this is and that you should stop but she can’t help but enjoy it. She tries to think clearly and when you pull out she’s relieved. You know though that this is what you both crave so you flip her on her belly and fuck her in doggy. She keeps asking - supposedly the universe - why it feels so go when it’s so wrong. She wants you to creampie her, she just doesn’t want to admit that this is how perverted she is.